Hydraulic slip joint pipe puller

ABSTRACT

A hydraulic slip joint pipe puller which pulls the spigot end of one pipe section into the gasketed, bell end of a previous pipe section remains in the trench, being rolled from one joint to the next, and is self-contained, having a storage battery and a motor and pump unit for supplying hydraulic fluid to a pulling cylinder and to a pair of clamping cylinders which are adapted to tighten a chain, band, webbing or the like around the respective pipe sections. A first base and a second base each have, at the bottom, depending side and end flanges, the latter having a concave, arcuate lower edge. The first base is attached to one pipe section and the second base to the other pipe section, so that a hydraulic pulling cylinder may pull the sections together. Telescoping, rigidifying tubes, such as a guide tube mounted on one base and a slide tube received in the guide tube and connected to the opposite base, resist lateral stresses when the pipe sections are being pulled together, thereby eliminating such stresses on the pulling cylinder and its piston rod. The pulling cylinder may be mounted below the guide tube, with its piston rod attached to an arm depending from the slide tube and the opposite end of the slide tube removably attached to an upright post on the opposite base. Or, the pulling cylinder may be within the telescoping tubes, in this instance rectangular in cross section but with rounded corners. The pulling cylinder is pivotally connected at one end to the outer or guide tube and its piston rod is pivotally connected to the opposite end of the slide tube, which is also attached to a bracket which upstands from the inner edge of the second base. A pair of spring mounted rollers at each end of the device raise the bases above the pipe, so that the device can be moved along the pipe sections on the rollers, but permit each base to solidly engage the pipe when the clamping bands are tightened. A pair of casters, at the front, may assist in rolling the front end of the device over the bell at the next joint, or the rollers may be laterally adjustable, so as to be spaced closer together for smaller pipe and farther apart for larger pipe. The clamping cylinders are mounted in an upright position on each base with a guide post at each side, while stress resisting slide tubes connected by a cross bar at the top engage the guide posts, with the piston rod connected to the cross bar and a chain link hook mounted on the outside of each slide tube. Or, a slide tube may surround a fixed guide tube, both of rectangular cross section with rounded corners, with a plate across the top of this slide tube connected to the piston rod. A chain hook is mounted on each lateral side of such a slide tube. A central lifting handle is used merely for lowering the device into the trench or lifting it out of it, while an enclosed battery, a motor and pump unit, a hydraulic reservoir and control valves are mounted above the guide tube.

Unite States Patent Mason, deceased HYDRAULIC SLIP JOINT llPE FULLER 22 Filed: Mar. 5, 1973 21 Appl. No.: 338,341

[76] Inventor:

Primary Examiner.lames L. Jones, Jr. Att0rney, Agent, 0r Firm-l-lorace B. Van Valkenburgh; Frank C. Lowe [57] ABSTRACT A hydraulic slip joint pipe puller which pulls the spigot end of one pipe section into the gasketed, bell end of a previous pipe section remains in the trench, being rolled from one joint to the next, and is self-contained, having a storage battery and a motor and pump unit for supplying hydraulic fluid to a pulling cylinder and to a pair of clamping cylinders which are adapted to tighten a chain, band, webbing or the like around the respective pipe sections. A first base and a second base each have, at the bottom, depending side and end flanges, the latter having a concave, arcuate lower edge. The first base is attached to one pipe section and the second base to the other pipe section, so that a hydraulic pulling cylinder may pull the sections together.

Telescoping, rigidifying tubes, such as a guide tube mounted on one base and a slide tube received in the 7 guide tube and connected to the opposite base, resist lateral stresses when the pipe sections are being pulled together, thereby eliminating such stresses on the pulling cylinder and its piston rod. The pulling cylinder may be mounted below the guide tube, with its piston rod attached to an arm depending from the slide tube and the opposite end of the slide tube removably attached to an upright post on the opposite base. Or, the pulling cylinder may be within the telescoping tubes, in this instance rectangular in cross section but with rounded corners. The pulling cylinder is pivotally connected at one end to the outer or guide tube and its piston rod is pivotally connected to the opposite end of the slide tube, which is also attached to a bracket which upstands from the inner edge of the second base.

A pair of spring mounted rollers at each end of the device raise the bases above the pipe, so that the device can be moved along the pipe sections on the rollers, but permit each base to solidly engage the pipe when the clamping bands are tightened. A' pair of casters, at the front, may assist in rolling the front end of the device over the bell at the next joint, or the rollers may be laterally adjustable, so as to be spaced closer together for smaller pipe and farther apart for larger pipe.

The clamping cylinders are mounted in an upright position on each base with a guide post at each side, whilev stress resisting slide tubes connected by a cross bar at the top engage the guide posts, with the piston rod connected to the cross bar and a chain link hook mounted on the outside of each slide tube. Or, a slide tube may surround a fixed guide tube, both of rectangular cross section with rounded corners, with a plate across the top of this slide tube connected to the piston rod. A chain hook is mounted on each lateral side of such a slide tube.

A central lifting handle is used merely for lowering the device into the trench or lifting it out of it, while an enclosed battery, a motor and pump unit, a hydraulic reservoir and control valves are mounted above the guide tube.

18 Claims jl tl Drawing Figures PAIEMEU um 1 51914 SHEET? 5 E MN I? PATENiIiU i 5314 1840.988

SHEEI n 0F 5 FARM-100m 15mm SHEET 5 0F 5 NIP HYDRAULIC SLIP JOINT PIPE FULLER This invention relates to a hydraulic slip joint pipe puller, and more particularly a device for forming a pipe joint by moving the spigot end of one pipe section into the bell end of an adjacent second pipe section within a trench in which the pipe is to be buried.

The present invention comprises a device which is particularly adapted to be utilized in the installation of relatively heavy water pipe, although it may be used for other types of pipe. Water pipe may be formed of duetile iron and is conventionally buried in a trench at a depth below the frost line of the geographical area involved, to prevent freezing of the water in the pipe during cold weather. Conventional present practice is to dig a trench, as by a backhoe, to a depth sufficient to place the pipe, when buried, below the frost line. Short cross timbers placed in the bottom of the trench may be utilized to permit each pipe section, in turn, to be slid into engagement with the previous pipe section, with the spigot end of a first pipe section entering the bell end of a second, previously laid pipe section. The bell ends of such pipe sections may be constructed in a suitable manner to receive a clamping gasket, which not only seals the spigot end of the next pipe section within the bell end, but also exerts a force to prevent separation of the joint. Of course, it requires a considerable force to move the spigot end of one pipe section into the gasketed, bell end of a previous pipe section, such as a force of on the order of 700 pounds for a inch diameter ductile iron pipe, of 950 pounds for a 30 inch diameter ductile iron pipe and of 1,100 pounds for a 36 inch diameter ductile iron pipe. A considerable length of trench may be initially excavated and a series of pipe sections lowered into the trench, one by one, and mechanical jacks utilized to push the spigot end of each pipe section, in turn, into the bell end of the preceding pipe section. However, this is extremely time consuming, and it is more conventional practice to utilize a backhoe to dig successive lengths of the trench corresponding to the length of the pipe sections, place the supporting timbers in the trench and then lower the next section of pipe into the trench by a cable sling hooked onto the bucket of the backhoe. When this sec- 1 tion of pipe is placed in the trench and aligned with the previous section as far as possible, the bell end thereof is nudged by the bucket of the backhoe to force the spigot end thereof into the bell end of the preceding section. However, heavy excavating equipment, such as a backhoe, does not have the refinement and control which permits the nudging of the pipe sections to be accomplished without the danger of a blow by the backhoe bucket which may damage the bell end of the pipe being nudged, so that it is unuseable.

While the successive portions of the trench are being excavated, the backhoe may deposit the earth being removed into a dump truck, which is then driven to a dumping point adjacent the pipe section previously in-, stalled and far enough away from the joint being made that there is no interference in that operation. Then, a bulldozer may be utilized to move the earth so dumped into the trench, the weight of the bulldozer also tamping the fill, so that the filling operation may proceed in synchronization with the excavation, a few pipe lengths behind the joint being formed.

The cable attached jack previously mentioned utilizes arms provided with fingers adapted to engage the opposite sides of the bell of a previous joint, to pull the pipe joint together, through a manually operated jack at each side of the pipe. However, such a device requires virtual dismantling and reassembly at the next 5 joint.

A pipe positioning and handling device has also, been proposed, in which a pair of clamps are utilized in grasping the next pipe section to be laid in the trench, with an abutment engaging the bell end of that pipe. This device is utilized to lift and place the pipe in the trench and is provided with an extension having a fork at its outer end which fits over the previous pipe section and engages the bell. A hydraulic cylinder pulls the pipe sections together, after which the device is unclamped clamped and then lifted by a crane or the like to the next pipe section. However, such a device requires the use of a separate crane or ties up the backhoe, if utilized as the lifting and lowering equipment for the pipe sections. In addition, such a device requires a separate source of hydraulic fluid, normally placed on the bank of the trench and connected by long hydraulic hoses to the device. Thus, whenever such a device is moved to the next pipe section, the hydraulic supply device must also be moved.

Among the objects of the present invention are to provide a hydraulic slip joint pipe puller which will effectively pull the spigot end of a first section into the bell end of a second, preceding pipe section, ithout interference with the operation of other equipment; to provide such a pipe puller which is a self-contained until provided with its own power supply, but without adding unduly to the weight thereof; to provide such a pipe puller which may be moved from joint to joint with ease and rapidity; to provide such a pipe puller which may be attached to and detached from the pipe sections to be pulled together with ease and with a minimum of time expended; to provide such a pipe puller which may be utilized with relatively heavy pipe without producing lateral stresses on the hydraulic mechanism which produces the force to pull one of the pipes into the other; to provide such a pipe puller which requires a minimum of personnel in the trench along with it; to provide such a pipe puller which solidly engages each of the respective pipes, when clamped thereto, but still may be easily rolled along the pipe from one joint to the next; to provide such a pipe puller, the weight of which is such that it may be readily rolled along the pipe, as by one man on each side; to provide such a pipe puller which may be lowered into the trench at the beginning of a shift and is not required to be removed from the trench until the end of the shift; and to provide such a pipe puller which is sturdy in construction but relatively simple in operation.

The foregoing and additional objects of the invention, as well as the advantages thereof, will become apparent from the description which follows, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a fragmentary, condensed side elevation of a machine constructed in accordance with this invention, in position to pull the spigot end of a pipe into the bell end of a previous pipe, within a trench in which the pipe is being laid;

FIG. 2 is a fragmentary, condensed side elevation similar to FIG. 1 but showing the machine after the spigot end of the pipe has been pulled into the bell end of the previous pipe, and also the bell end of that pipe and the spigot end of the next pipe;

FIG. 3 is a fragmentary, vertical section, on an enlarged scale, taken along line 33 of FIG. 1 and showing an end elevation of the machine;

FIG. 4 is a side elevation of the machine on a slightly smaller scale than FIG. 3, with the parts of the machine being in the same position as in FIG. 1;

FIG. 5 is an end elevation of the machine as shown in FIG. 4, but taken at the opposite end of the machine from that shown in FIG. 3;

FIG. 6 is a fragmentary top plan view of a portion of the machine of FIG. 4, showing particularly a hydraulic pump and reservoir, as well as one of the clamping means or hydraulic devices for tightening a chain or belt about the pipe which is to be pulled;

FIG. 7 is a fragmentary, horizontal section taken along line 7-7 of FIG. 5, through one of the aforesaid hydraulic devices;

FIG. 8 is a fragmentary, horizontal section, taken along line s s of FIG. 4;

FIG. 9 is a vertical section taken along line 99 of FIG. 4, adjacent one end of the machine and looking toward that end;

FIG. 10 is a vertical section taken along line 1010 of FIG. 4, at the same end of the machine;

FIG. 11 is a vertical section taken along line 11-11 of FIG. 4, at the opposite end of the machine;

FIG. 12 is an electrical and hydraulic diagram illustrating particularly the hydraulic connections of the machine;

FIG. 13 is a side elevation of an alternative pipe puller forming an additional embodiment of this invention;

FIG. 14 is a top plan view of the pipe puller of FIG. 13;

FIG. 15 is an end elevation of the right hand end of the pipe puller of FIG. 13;

FIG. 16 is a fragmentary section, on an enlarged scale and taken along line l616 of FIG. 13, showing the resilient mounting of a pair of laterally adjustable rollers;

FIG. 17 is a vertical section taken along line 1717 of FIG. 13 through the hydraulic device utilized in attaching the pipe puller to the pipe which is to be pulled into the previous laid pipe section; and

FIG. 18 is a fragmentary, vertical section taken along line 18-18 of FIG. 13, through a rigidifying, telescoping means in which a pulling hydraulic cylinder is installed adjacent the outer end thereof.

In FIG. 1 is shown a pipe section 10 having a bell end 11 which has previously been installed in a trench T and the next pipe section 12, which has been placed in the trench, with the pipe sections resting on timber supports 13, to permit the pipe sections to be slid more readily longitudinally in the trench, so as to push the spigot end 14 of pipe section 12 into the bell end 11 of pipe section 10. A pipe puller constructed in accordance with this invention is shown in FIG. 1 as connected to the pipe sections 10 and 12 adjacent the respective spigot and bell ends, while in FIG. 2 is shown the pipe puller after the spigot end of pipe section 12 has been moved into the bell end of pipe section 10. The next pipe section 15 is also shown in FIG. 2 positioned so that, as soon as the pipe puller is disconnected from the pipes 10 and 12, it may be rolled along the pipe section 12 to the next joint and then extended,

so as to be clamped to the pipes 15 and 12, preparatory to pulling the spigot end 14 of pipe section 15 into the bell end 11 of pipe section 12. The bottom 16 of the trench is preferably at a sufficient distance below the ground level 17 that the entire pipe will be below the frost line, while the sides 18 of the trench are at least spaced apart sufficiently to permit the pipe sections to be installed and workmen to move around them without undie difficulty. Depending upon the stability of the earth into which the trench T is dug and the tendency for any cave-ins, the sides 18 of the trench may be generally upright or sloped outwardly, while in less stable earth, particularly in the case of a relatively deep trench, shoring or other safety provisions should be utilized. In the geographical area of Colorado Springs, Colorado, the bottom 16 of the trench will be on the order of 8 feet below the ground level 17. As the operation proceeds, the back fill 19 may be pushed into the trench, as by the bulldozer previously mentioned. It will be understood that the angle of back fill 19 is shown in FIGS. 1 and 2 as considerably greater than in actual practice, in order to conserve space on the drawing. Thus, the back fill 19 will, in normal operations, actually slope upwardly at an angle of perhaps between 20 and 30 to the horizontal.

The pipe puller of this invention includes a main base B adapted to engage and be clamped against the pipe whose spigot end is to be pulled into the bell end of the next pipe, and an auxiliary base A adapted to engage and be clamped against the pipe having the bell end. A telescoping, rigidifying means R connects the base B with the base A for relative movement, while a hydraulic cylinder H is utilized in moving the bases between the extended position of FIG. 1 and retracted position of FIG. 2, and vice versa. A hydraulically operated clamping means C is mounted on base B, while a hydraulically operated clamping means C is mounted on base A. An electrical energy means E, such as a storage battery within a protective case, is mounted on base B, while a combined electric motor and hydraulic pump MP for supplying hydraulic fluid, shown in other figures and identified more particularly later, is mounted beneath a control valve assembly V, through which the appropriate supply of hydraulic fluid under pressure and the withdrawal thereof from the cylinder means H and the clamping means C and C are controlled. Each of the clamping means C and C is adapted to produce tension through a chain 20 at each side, to provide adjustability for different pipe sizes, while a belt or webbing 21 extends around the respective pipe. For such adjustability, each clamping means C and C is provided with a hook 22 at each side, as in FIG. 3, with which an appropriate link of the chain 20 may be engaged, to compensate for variations in the circumference of the pipe, such as having a nominal diameter of 20 inches, 30 inches or 36 inches. Hooks 22 permit an appropriate number of links of chain 20 to be dropped when a smaller size of pipe is to be clamped.

As illustrated in FIGS. 4 and 8, the rigidifying means R includes an elongate, inner cylindrical tube 24 which moves longitudinally within a shorter cylindrical guide tube 25, which is mounted on the main base B and extends from each end thereof. A suitable lubricant, such as grease, is placed inside the guide tube 25 and on be outside of inner tube 24. At the front end of base B, the inner tube 24 moves freely with respect to the base B, but the front end is closed by a cap 26 which may be formed integrally with the tube or may be welded thereto. In addition, a depending arm 27 is welded to the underside of tube 25, at its forward end, for pivotal attachment of a clevis 28 through a pivot pin 29, with the clevis 28 being attached to the front end of the piston rod 30, shown in FIG. 9, of hydraulic cylinder means H. An expandable cover 31 encloses the portion of the front end of the inner tube 24 which may move inwardly and outwardly of guide tube 25, to protect tube 24 from collecting dirt or other debris which might interfere with the lubrication of tube 24 during movement within guide tube 25. Cover 31 may be attached by clamping rings 32 such as a conventional hose clamps, to inner tube 24 adjacent depending arm 27 and to the outside of guide tube 25. A guiding handle 33 may also be attached, as by welding, between the top of tube 24 and the front end of depending arm 27, to facilitate the operator rolling the pipe puller along the pipe from a completed joint to the next joint to be pulled. The rear end of inner tube 24 may be attached, as by welding, to a cylindrical block 34 which fits into an attachment tube 35 mounted atop the auxiliary base A, with block 34 being removably attached, as by bolts 36 of FIGS. 4 and 8, to the attachment tube 35 for assembly purposes, i.e. to permit the inner tube 24 to be inserted into the guide tube from the rear, since depending arm 27 will prevent insertion from the front end and permanent attachment of tube 24 to auxiliary base A would prevent insertion from the rear end. The exposed lubricated area of tube 24, which moves inwardly and outwardly at the rear end of guide tube 25, is again protected against dirt and debris by an expandable cover 31 which is attached to the outside of guide tube 25 and the outside of attachment tube by clamps 32, which may again be conventional hose clamps. The rear end of attachment tube 35 may be closed by a cap 26, which may be integral therewith or welded thereto, while a rear guide handle 33' may be attached, as by welding, to the top of attachment tube 35.

The length of guide tube 25 should be such that lateral stresses in any radial direction produced by any slight misalignment of the pipe section, whose spigot end is to be pulled into the bell end of the previously laid pipe section, will be resisted by the bearing area between tubes 24 and 25, so that little, if any, lateral stress will be imposed on the hydraulic cylinder means H, particularly those which might cause misalignment of its conventional piston inside its cylinder 38. The hydraulic cylinder means H may be of conventional construction, with cylinder 38 provided with end caps 39 and 40, the two being connected by tension rods 41 and the former being provided with a packing gland 42. The exposed portion of the piston rod of the hydraulic cylinder means H may be protected against dirt or debris by an expansible cover 43 attached by clamping rings, as shown, to the packing gland and the piston rod adjacent clevis 28, respectively. The end cap of cylinder 38 may be provided with a conventional longitudinally extending ear for pivotal attachment, through a pin 44, to a three-sided bracket 45 of base B, through the sides of which pin 44 extends. A clamp 48 may be welded to the rear of bracket 45, so that laterally extending rod (not shown) may be attached, to be grasped by the operators in moving the pipe puller along the pipe.

The main base B includes, at the bottom, a plate 48 having depending side flanges 49 and depending front and rear flanges 50, with the side flanges conveniently being integral with the plate 48, so that a conventional channel may be used to form the bottom of the main base. The end flanges 50 are welded to the ends of this channel, with the lower edge of each being cut along an are, as in FIG. 9. The radius of this arc may correspond to the diameter of the smallest size of pipe to be pulled, such as 20 inches, so that the lower edges of the end flanges will solidly engage the smallest pipe and the lower edges of the side flanges 49 will solidly engage a pipe of a larger diameter. The three-sided bracket 45 may, of course, be welded to the plate 48, while an upstanding lug 51 may be welded to the top of plate 48, at each side of the cylinder 38, and a heavy strap 52 may be removably attached, as by bolts as shown, to the lug Sll, at each side. Strap 52 is curved to correspond to the outer diameter of the guide tube, when extending thereover, so that the guide tube 25 may be welded to the underside of the strap, and strap 54 will support guide tube 25 rigidly at one end. The opposite end of guide tube 25 is supported by three-sided bracket 45, the rear wall of which may be grooved to correspond to the underside of the guide tube and welded thereto. A bar 53 may extend angularly upwardly from each side of bracket 45 to the underside of a battery support 54, the body of the battery 55, indicated in FIG. 12, preferably being surrounded by an enclosure 56, the top of which is closed by a cover 57. The enclosure and cover for the battery may be formed of styrofoam or other suitable material, to protect the battery against dirt or debris. The battery enclosure and cover, along with the battery, are clamped against the battery support 55 in any suitable manner, such as by rods 58 attached to the support 55 and threaded at the upper ends for reception of wing nuts, as shown, to clamp a bar 59 against the cover 57, as in FIG. 5. The battery cover 57 may be provided with a boss 60 at each side having a downwardly extending opening through which a battery cable 61 or 61 may extend.

An angular bracket 62 having a tapering flange at the rear, whose underside is cut out to conform to the diameter of the guide tube 25 and welded thereto, sup ports a conventional 12 or 24 volt electric motor and hydraulic pump MP, such as the Monarch Dyna- Might hydraulic power plant. Also mounted on bracket 62, as in FIG. 6, are a hydraulic reservoir 64 and a pair of control valves 65 and 66 having respective handles 67 and 68 for controlling the flow of hydraulic fluid to the hydraulic cylinder means H and the clamp ing means C and C, respectively. Clamping device C may be mounted on an inverted U-shaped bracket 63, the underside of each of the depending flanges of which are cut to the contour of the guide tube 25 for welding thereto. An angular lifting handle 69, adapted to be engaged by a hook suspended by a sling from the backhoe bucket or any other suitable lifting device, is attached, as by welding, to a cross bar 70 which extends across and is welded to the upper ends of a pair of rods 71 which upstand from and are attached, as by welding, to the rear end of bracket 62. Any other suitable construction of a centrally disposed lifting handle may, of course, be utilized.

The auxiliary base A, although shorter than main base B, includes a similar plate 48' having depending side flanges 49', which again maybe welded to or integral with plate 48' so that a channel may be used, as well as depending end flanges 50' having an arcuate lower edge, as in FIG. 5, corresponding to the arcuate lower edge of end flange 50 of FIG. 9. Welded to plate 48 is an upstanding post 72, to the top of which is welded the attachment tube 35. The clamping means C is mounted directly on top of the plate 48 of the auxiliary base A. The clamping means C and C are quite similar in construction, so that a description of one will be equally applicable to the other. Thus, as in FIGS. 4, and 7, the clamping means C includes a cylinder 38 extending between end caps 39 and 40, with tension rods 41 extending between the end caps. How ever, end cap 40 is mounted on a base plate 74 which is attached, as by bolts, to the plate 48 of auxiliary base A, in the case of clamping means C, and to the platform 62 in the case of the clamping means C. Base plate 74 extends laterally to each side and is provided with a socket at each side for receiving a fixed, upstanding guide shaft 75 which is received in a depending guide tube 76, the upper ends of the latter being connected together by a cross bar 77, as of hollow, rectangular cross-section. Piston rod 30 is attached to the underside of the cross bar 77, as by a socket connection 78, while end cap 39 is also provided with a packing gland, as shown. The hydraulic connections to the hydraulic cylinder means H and clamping means C and C will be described later. However, as will be evident, the guide shafts 75 and guide tubes 76 act to prevent any lateral stress on the hydraulic cylinders 38, thereby preventing tipping or canting of the piston rod and piston thereof. For connection to hooks 22, a pair of parallel brackets 79, as in FIGS. 7-7, are welded to the outside of each guide tube 76, while a pivot pin 80, such as a bolt, extends between the brackets for pivotally mounting the respective hooks 22. The hooks 22 may have a suitable configuration, such as that shown, for receiving a desired link of the chain 20.

The main base B is provided, at the front, with a pair of front rollers 82 and a pair of centrally located lift casters 83. The front rollers 82 are utilized in moving the machine along the pipe between joints, while the lift casters 83 are utilized in lifting the main base B over the bell, at the next joint, particularly for smaller diameter pipe, where the diameter of the bell is such that, with the front rollers 82 spaced from the longitudinal centerline of the bell, they do not quite lift the front end of the main base B over the bell. The auxiliary base A is provided with a pair of rear rollers 84 which are also utilized in rolling the pipe puller along the pipe. Each of the front rollers 82, lift casters 83 and rear rollers 84 are spring mounted, the springs being sufficiently heavy that, when the belt or webbing 21 of FIGS. 1 and 2 is released from the pipe, the front and rear rollers will elevate both the main base and auxiliary base above the pipe, as in the position of FIG. 5, in which the outer surface of the pipe is indicated by the dotted line The front rollers 82, as in FIGS. 3, 9 and 10, may each be mounted on a stub shaft 85, each of which extends from a front axle 86 which is movable upwardly and downwardly within a series of slots 87 in the sides of open bottomed, spring retaining boxes 88 which are attached, as by welding, to the front edge of the base plate 48. A guide pin 89 for a compression spring 90 is attached to and upstands from the top of axle 86, extending upwardly through a hole in the top of box 88. Nuts 91 are attached to the threaded upper ends of guide pins 89, to prevent either of the springs, which are under compression at all times, from forcing a guide pin downwardly out of the respective box.

The lift casters 83, as in FIGS, 3 and 4, are inclined slightly toward each other, as in FIG. 3, being mounted for rotation in a conventional clevis 92 having a post 93 which extends upwardly through a compression spring 94, bearing between a disc 93a fixed to the post and an upper flange of mounting bracket 95 attached to the front of the respective box 88, a lower flange of bracket 95 being a stop for disc 93a.

The rear rollers 84, as in FIGS. 5 and 11, are mounted on stub shafts extending from the ends of a rear axle 86, which is movable upwardly and downwardly within slots 87 formed at the ends of a single box 96, which is mounted on the rear end of plate 48, as by welding. A series of guide pins 89 are mounted on the top of rear axle 86, so as to extend centrally upwardly within one of three compression springs and are threaded, at their upper ends, for attachment of nuts 91'. In this instance, the nuts 91 clamp to the guide pins 89 a laterally alongated bar 97 which extends at each side over the respective rear rollers 84 for connection to the extended end of the corresponding stub shaft 85, as by a rod 98 having a socket 99 at its lower end, to receive the corresponding stub shaft 85'. Rod 98 is threaded at the upper end for attachment by similar nuts 91 to the corresponding end of the bar 97. The purpose of the bar 97 is to assist in maintaining the rear rollers 84 in lateral alignment as they move over the bell and along the pipe, since the rollers 84 follow behind the pipe puller, rather than being pushed ahead, as are the front rollers 82.

The hoses which connect the control valve 85 with the hydraulic cylinder means H include, as in FIGS. 6 and 12, a hose 102 which extends to a hole in the rear end cap 40 for the cylinder 38 and a hose 103 which extends to the front end cap 39 for the cylinder 38. As will be evident, when the handle 67 for valve 65 is moved in an appropriate direction, hydraulic fluid under pressure will be supplied through hose 102 to hydraulic cylinder means H to extend the same and thereby push the inner tube 24 through the guide tube 25 and simultaneously move the auxiliary base A toward the main base B, thereby pulling the spigot end of the pipe to which base B is connected into the bell end of the pipe to which auxiliary base A is connected. Of course, with the valve in this position, fluid on the opposite side of the piston within cylinder 38 will be exhausted back to the reservoir 64 through hose 103. This will be evident from the direction of the arrows associated with the diagrammatic showing of the hoses 102 and 103 in FIG. 12. A pressure gauge 104 may conveniently be placed on the discharge side of the valve to measure the pressure of fluid supplied through hose 102 to extend the piston rod 30, since the pressure to be generated by the pump, in order to move the spigot end of one pipe into the bell end of the previous pipe, depends upon the diameter of the pipe, as indicated previously. In FIG. 12 is also shown battery 55, a switch 106 associated with battery cable 61', for turning the hydraulic motor on and off, with the motor being indicated as M and the pump as P, and the same being shown directly connected together, even though the actual unit is totally enclosed in an essentially unitary construction.

As in FIGS. 4, 6 and 12, hoses 108 and 109 extend from a pipe 110 connected to control valve 66 on the lower end caps 40 for the hydraulic cylinders of he respective clamping means C and C, and thus supply hydraulic fluid under pressure to move the clamping means upwardly and tighten belt or webbing 21 about the respective pipes. This tightening is preferably done simultaneously for both clamping means. Hoses 111 and 112 extend from a pipe 113 connected to the opposite side of control valve 66, as in FIG. 6, to the upper ends of the hydraulic cylinders of clamping means C and C, as in FIGS. 3, 4 and 12, for exhausting fluid from the upper end of the respective cylinder 38', when the clamping means are'being lifted to tighten belt 21 about the respective pipes. Hoses 111 and 112 also supply hydraulic fluid under pressure to the cylinders, when the clamping means are to be retracted for loosening of the belts 21 and removal of one chain from its hook 22, after the pipe joint has been pulled and the pulling device is to be moved to the next joint. When the clamping means are retracted, of course, hydraulic fluid will be exhausted from the bottoms of the cylinders through hoses 108 and 109. The lifting operation is illustrated diagrammatically by the arrows of FIG. 12, in which hydraulic under pressure is being supplied through pipe 110 and hoses 108 and 109 to the lower ends of the cylinders of the clamping means C and C, respectively, while hydraulic fluid is being exhausted through hoses 111 and 112 into pipe 113 and back to the reservoir 64 at the same time. A pressure gauge 1 14 may be placed in the hydraulic line for extension of the clamping means C and C, in order to determine the hydraulic pressure exerted within the hydraulic cylinders of the clamping means C and C, to insure adequate clamping of the pipe.

In general, after the machine is placed on the two pipes to be pulled together to make the joint, as in FIG.

1, but without the chains 20 and webbing 21 connected, one chain for each belt is placed ove the respective hook, with the clamping means C and C retracted, the belt and opposite chain passed under the pipe and the opposite chain connected to the opposite hook of the corresponding clamping means. A link of the chain is selected which will permit the belt to be moved manually against the pipe as snugly as possible. Then, the switch 106 of FIG. 12 is closed to start the motor M which drives the hydraulic pump P. Of course, the usual relief valve is provided, so that pressure above a predetermined amount is exhausted back to the reservoir 64. Then, the handle 68 of the control valve 66 of FIG. 6 is moved to an appropriate position to cause hy draulic fluid to be supplied through pipe 110 and hoses 108 and 109 to the hydraulic cylinders 38 of clamping means C and C, in order to extend the same, as indicated by the arrows of FIG. 12. As soon as an appropriate pressure is observed at gauge 114, the control valve handle 68 is moved to a central position, in which hydraulic fluid flows neither in nor out of the hydraulic cylinders of the clamping means, thereby maintaining base B tightly clamped against the pipe 12 of FIG. 1 and the auxiliary base A tightly clamped against the pipe of FIG. 1. This permits the entire discharge of pump P to be available for pulling the pipe joint. Thus, the handle 67 of control valve 65 of FIG. 6 may then be shifted to a position to supply hydraulic fluid under pressure through hose 102 to hydraulic cylinder 38, thereby extending piston rod 30 and pulling the two pipes together to the position of FIG. 2. When this position is reached, the control handle 67 may be moved to a neutral position, but the control valve handle 68 may then be moved to a position to retract the clamping means C and C and then to a neutral position. At that time, the belts 21 will be loose around the corresponding pipes and the chains 20 may be disconnected from the respective hooks 22. The switch 106 may, of course, be opened. Then the entire machine may be moved along the pipe, sincewhen the belts 21 are released, the compression springs associated with the front and rear rollers will elevate the main base and auxiliary base above the pipe. It is preferable to roll he pipe puller along the pipe with the main base B and auxiliary base A as close together as possible, so that the auxiliary base A will be better able to clear the bell at the joint just completed, such as the bell 11 of pipe 10 of FIG. 2. The machine may be rolled along the pipe by an operator at each side grasping front handle 33 and rear handle 33. When the next pipe bell end is reached, the front rollers 82, assisted by the lift casters 83, are moved over the bell end until the main base B has cleared the bell end. Then the switch 106 is turned on again and the control valve handle 67 moved to a position to supply fluid to and from hydraulic cylinder 38 in a direction the reverse that of the arrows of FIG. 12, i.e. to retract the piston rod 30 within cylinder 38 but to move auxiliary base A away from main base B, as to the position of FIG. 1. Then, the valve control handle 67 may be moved to a neutral position and the belts 21 passed around the pipes and the chains connected to hooks 22, in the manner previously described.

The machine may, of course, remain within the trench on the pipe during a complete shift, as indicated previously. Two batteries 55 are preferably utilized, with one being charged while the other is being used, since a heavy duty 12 volt battery will last from 10 to 12 hours before recharging becomes necessary. In addition, the pipe puller does not interfere with the normal operations of digging the trench, fitting the pipe into the trench, or filling after the joints are completed, since as soon as one section of pipe has been placed in the trench, the pipe puller may be used to produce the joint, while the backhoe or similar heavy equipment is digging a further length of the trench. Also, as soon as one joint has been completed and the pipe puller rolled toward the next joint, the filling operation may proceed to cover up the joint just completed, if desired, In fact, a machine constructed in accordance with the embodiment of FIGS. 1-12 weighing 420 pounds has been utilized successfully in pulling the joints for many hundreds of feet of water pipe of each of 20 inch, 30 inch and 36 inch diameter. In addition, in some instances, the machine has rounded out pipe which was eggshaped and pulled it into the joint.

The embodiment of this invention illustrated in FIGS. 13-18 incorporates the principles of operation of the first embodiment, but utilizes a somewhat shortened main base B and places the hydraulic cylinder H in a protected position within the rigidifying means R, although the clamping means C and. C are placed in essentially the same position. Also, the rigidifying means R and the clamping means C and C are somewhat modified to provide a greater resistance to torsional stress for the former and an alternative guiding means for the latter. As before, a motor pump unit MP is mounted on the main base B, as well as a control valve assembly V and electrical energy means E. Also, the

main base B is provided with a pair of spring mounted front rollers 82 and the auxiliary base A with a pair of spring mounted rear rollers 84'. Due to the shortening of the machine, as well as the fact that the rollers 82 and 84 are laterally adjustable to accommodate different pipe diameters, in a manner described later, it was found unnecessary to utilize lift casters corresponding to casters 83 of FIGS. 3 and 4.

The main base B, as in FIGS. 13 and 18, includes a plate 120 having side depending flanges 121, which may be welded to or may be integral with the plate, so as to be formed from a channel, as before, and depending end flanges 122, each welded to plate 120 and the lower edge cut along an arc, as in FIG. 17, as along a radius corresponding to the diameter of the minimum pipe size for which the puller is intendd to be used. Similarly, the auxiliary base A includes a plate 120' having side-depending flanges 121, which may be welded to or integral with the plate, so that a channel may be used, and depending end flanges 122, each welded to plate 120 and the lower edge out along an are are similar to flanges 122. An upstanding, three-sided bracket 123 having rearwardly and downwardly sloping side edges is welded around the bottom to plate 120 of auxiliary base A and a front wall 124 thereof extends upwardly from the transverse front edge of plate 120, for a purpose described below.

The rigidifying means R comprises an inner tube 125 and an outer tube 126 formed of interfitting, hollow rectangular tubing provided with rounded corners, with the inner tube 125 and outer tube 126 being sized for relatively easy sliding movement therebetween when lubricated, but otherwise with as tight a fit as possible to withstand not only lateral stresses, but also torsional stresses. The rear end of inner tube 125 is welded to the front face of front wall 124 of bracket 123 of auxiliary base A, while the outer tube 126 is mounted above the base plate 120 of main base B. on a pair of brackets 127 and 128 attached, as by welding, to the outer tube at a central position and a position near the front end thereof, respectively. The side flanges of each bracket 127 and 128 extend upwardly along the sides of the outer tube 126 for welding thereto, while the upper edge of an angle web 129 of each bracket, as in FIG. 18, is welded to the underside of the outer tube 126. The lower flange of each angle web 129 may either be bolted or welded to the base plate 120 of the main base.

The hydraulic cylinder means H is installed within the inner tube 125, so as to be in a protected position, and includes a conventional cylinder 130, the front end of which is provided with an ear 131, as in FIGS, 13, and 18, pivotally connected to the front end of outer tube 126 by a pin 132 which extends through a hole in the ear and holes in a pair of cylindrical bearing blocks 133 welded in opposed, central lateral positions to the inside of outer tube 126 at the front end thereof. Pin 132 is insertable from the outside for assembly purposes, then retained in position by suitable retaining means, such as a cotter pin 134 at each end. A slot 135, which extends past the bearing blocks 133, is provided in each side of the front end of inner tube 125, to accommodate movement of the inner tube to the position of FIG. 13, which is its retracted position. From the rear end of cylinder 130, as in FIG. 13, a piston rod 136 extends through a packing gland and to a socket 137 to which it may be threadedly attached. Socket 137 is pivotally connected to the rear end of inner tube 125, through a pin 132 which extends through a pair of cylindrical bearing blocks 133, similar to bearing blocks 133 but welded to the inside of inner tube 125. A pin 132 similarly may be inserted from the outside, for assembly purposes, and after insertion, may be retained in position in any suitable manner, as by cotter pins similar to cotter pins 134. Pin 132 is positioned so that it will be disposed rearwardly of the rear edge of outer tube 126, when the inner tube is pulled to the retracted position of FIG. 13, to prevent the pin from striking the outer tube. A cover may be provided for the open end of outer tube 126, while an expansible cover similar to covers 31 and 31' of FIG. 4, may be provided for the portion of inner tube exposed when the auxiliary base A and main base B are moved apart.

Although the pipe puller of FIGS. 13-18 is essentially shorter in overall length than the pipe puller of FIGS. 1-12, it will be noted that the cylinder of the hydraulic cylinder means H of FIG. 13 has essentially the same length as the cylinder 38 of FIG. 4. Thus, the distance through which the main base B and auxiliary base A may be pulled toward each other is essentially the same distance as that for the main base B and auxiliary base A of the embodiment initially described. One difference, of course, between the two embodiments is that the hydraulic cylinder means H of FIGS. 1-12 is extended to pull one pipe into the other, while the hydraulic cylinder means of FIGS. 13-18 is retracted to pull one pipe into the other. Since the area occupied by the piston rod lessens the total area against which hydraulic pressure is exerted to pull the pipe, cylinder 130 of FIG. 13 should perhaps be larger than cylinder 38 of FIG. 4, the motorpump MP would normally have sufficient capacity to provide the required pressure, for larger sizes of pipe.

A battery support 54 may be mounted directly on top of the outer tube 126, with a slight overhang to the rear, while the battery enclosure 56, top cover 57, clamping rods 58 attached to support 54' and top bar 59' of FIG. 14 may be essentially the same in construction as the corresponding parts of the embodiment initially described. As before, the cover 57 may be provided with a laterally extending boss 60, at each side, which permits battery cables, not shown but similar to battery cables 61 and 61' of FIG. 5, to extend to the motor pump unit MP, as through a switch corresponding to switch 106 of FIG. 12. The motor pump unit MP, reservoir 64, valves 65' and 66 and also clamping means C are mounted on a plate 140 which is attached to the top of outer tube 126 and extends laterally a sufflcient distance to accommodate the motor pump unit MP and the hydraulic fluid reservoir 64, but narrows at the front, so as to avoid interference with the chains and webs tightened around the pipe, which are similar to chains 20 and web 21 of FIGS. 1 3 and tightened by clamping means C.A handle 69, which may be essentially an inverted, heavy, U-shaped rod, the lower ends of which are attached, as by welding, to the top of outer tube 126 at a central location, may also be provided for lifting the pipe puller in and out of the trench. This handle, as well as the sides of the bracket 123, provide convenient parts for the operators to grasp, when rolling the pipe puller along the pipe between joints.

As before, the clamping means C and C are similar in construction; thus, a description of one is equally applicable to both, the two differing only in that clamping means C is mounted atop outer tube 126, in turn mounted on main base B, while the clamping means C is mounted on the base plate 120' of the auxiliary base A. Clamping means C is shown in section in FIG. 16 and includes a cylinder 141 having a lower end cap 142 provided with flanges 143 by which the cylinder may be attached, as by bolts 144, to the base plate 121). Cylinder 141 is also provided with an upper end cap 145 having a packing gland 146, through which a piston rod 147 extends to a ball and a socket joint 1418, into which a bolt 149 extends from above, with a lock nut 150 provided, for a purpose described below. The clamping means C further includes an upstanding, tubular guide 151 which may be rectangular but provided with rounded corners, and the lower edge of which is attached, as by welding, to the base plate 120'. Slidable upwardly and downwardly on the outside of guide tube 151 is a slide 152, which is also tubular and conveniently rectangular in cross section but with rounded corners and sized to fit closely over the guide tube 151, to slide readily therealong when lubricated, but with a sufficiently tight fit to resist not only lateral stresses in either direction, but also torsional stresses. The slide 152 is provided, at its upper end, with a top plate 153 which may be attached, as by welding, to the upper edges of slide 152 and reinforced on the inside by triangular gussets 154, welded at the center of each of the four sides. The bolt 149, which may be locked in an ad justed position by lock nut 150, attaches the piston rod 147 to top plate 153. A hook 155 of suitable construction is attached, as by welding, to a reinforcing plate 156, in turn attached by welding to the respective lateral sides of the slide 152. Each hook 155 maybe provided at its lower end with a pair of spaced prongs 157, so that a link of chain may be placed on top of the prongs, with the next link below extending downwardly in the slot between the prongs, as well as a link being hooked over the prongs. As will be evident, whenever piston rod 147 of the clamping means C is extended by hydraulic fluid supplied to the bottom of cylinder 141, the books 155 will be raised with the slide 152, but the guide 151 will resist lateral stress in either direction, as well as torsional stress, and thus prevent the possibility of piston rod 147, or the piston to which it is connected inside cylinder 141, from becoming misaligned. It will be evident that the pair of guide shafts 75 of FIG. 7 will also resist not only lateral stresses, but also torsional stresses. It will further be understood that the hooks for the clamping means C and C of this second embodiment may be constructed similarly to the hooks 22 of the previous embodiment, or in any other suitable manner.

The front rollers 82' and rear rollers 84 are similarly mounted at the front and rear ends of the respective bases B and A through a three-sided, upstanding bracket 160 attached, as by welding, to the top of plate 120, at the front end thereof, and a similar, but oppositely facing, three-sided bracket 160 similarly attached to the top of plate 120, at the rear end thereof. Each roller 82 and 84 may be provided with a suitable bearing 161, as of the ball type, mounted on a reduced outer extension 162, as in FIG. 16, of a stub shaft 163 which extends into a tubular shaft housing or axle 164. The construction of the parts associated with the rear rollers 84 is the same as for the front rollers 82' and, as in FIG. 16, shaft housing 164 is provided with a series of laterally spaced holes 165, through a spaced pair of which and through a corresponding hole in each stub shaft 163, a bolt 166 extends. As will be evident, bolt 166 may be placed in different holes 165 for adjusting the position of rollers 82 and also rollers 84 laterally, in order to accommodate different pipe diameters and particularly to permit the rollers to ride over a bell 11 of a pipe.

As before, each pair of rollers 82' and 84 act against a series of compression springs, such as springs 167, which may be three in number and each disposed within an upright tube 168, with the tubes 168 being attached, as by welding, to the respective front or rear face of the bracket 160 and 160'. Each tube 168 has a closed upper end and an open lower end, but with a fixed or stationary disc 169 inside and spaced below the upper end, disc 169 being attached, as by tack welding, to the inside of tube 168. Thus, the upper end of each spring 167 bears against the underside of a fixed disc 169. A lower disc 170, attached, as by welding, to an upstanding pin 171, engages the lower end of each spring 167, while a series of tack welds 172 may be spaced around the inside lower edge, otherwise open, of each tube 168, to prevent spring 167 from forcing disc 170, and pin 171 along with it, out the lower end of the corresponding tube 168, when there is no upward pressure against the springs. Pins 171 are, of course, attached at their lower ends, as by welding, to the shaft housing 164, so that pins 171 will move upwardly and downwardly with shaft housing 164 and rollers 82' or 84. Pins 171 may be welded to housing 164, then discs 171) welded to the pins and springs 167 placed over the pins and inserted into tubes 168. The springs 167 may be compressed in a suitable jig, by which pins 171 are pushed inwardly so that each disc 170 will be spaced from the open end of the tube, to provide clearance for placing the tack welds 172. The central holes in upper disc 169 and lower disc 170 guide the pins 171 upwardly and downwardly and retain them in an upright position, thereby also holding rollers 82 and 84 in the desired fore and aft position. It will be understood, of course, that other suitable constructions for providing spring pressure against the supporting rollers may be utilized, so as to hold the main base B and the auxiliary base A upwardly and off the pipe, when the clamping means C and C are released, but to permit the respective bases B to be moved downwardly into clamping engagement with the pipe, when the clamping means C and C are utilized to pull a chain, belt, webbing or the like against the pipe.

Since the pipe roller will normally be used during a full working day on the same size of pipe, the lateral adjustment of rollers 82' and 64' may easily be made before the pipe puller is lowered into the trench for use. Thus, the rollers 82' and 84 may be adjusted closer to gether for smaller pipe and farther apart for larger pipe, so that no particular difficulty will be encountered in rolling the pipe puller along the pipe between joints, and particularly in rolling the main. base B over the bell end of a pipe.

The hydraulic controls and electrical power supply for this second embodiment are essentially the same as illustrated in FIG. 12 for the embodiment initially described. Thus, hoses 102 and 103 may lead from valve to the respective ends of the cylinder of the hydraulic cylinder means H. These hoses conveniently enter the open outer end of the outer tube 126 and extend inside the tube above the ear 131 and bearing blocks 133 and connected through conventional fittings 175 to cylinder 130. Hose 102 is adapted to supply hydraulic fluid under pressure to one end of the cylinder for the purpose of retracting piston rod 136 and pulling the pipes together, while hose 103 is adapted to supply hydraulic fluid under pressure to the opposite end of cylinder 130, for extending piston rod 136 and moving the bases B and A apart.

Hoses 108 and 109 lead from a pipe 110 at valve 66 to the respective lower ends of the cylinders 141 of the clamping means C and C, in order to supply hydraulic fluid to the cylinders to raise the hooks 155 and thereby tighten the webs, belts or the like around the respective pipes. Hoses 111 and 112 lead from a pipe 113, also at valve 66', for supplying hydraulic fluid under pressure to the upper ends of the cylinders of the clamping means C and C, to retract the piston rods thereof and loosen the belt, webbing or the like clamped around the pipes. The hoses 108 and 111 may be connected to the cylinder of clamping means C and the hoses 109 and 112 similarly connected to the cylinder of the clamping means C by conventional fittings 176. The fittings 176 may extend through holes 177 of FIG. 15 in the guide tube 151, with a lower hole 177 being below the retracted position of slide 152 but a slot 178 being provided in one side of slide 152, to permit the corresponding fitting 176 to extend through upper hole 177, in the guide tube 151, while the slide 152 moves upwardly and downwardly.

As will be evident, the operations involved in the use and control of this second embodiment are essentially the same as those described in connection with the first embodiment. It will be understood, of course, that a pressure gauge corresponding to gauge 104 of FIG. 12 may be provided to indicate the pressure of hydraulic fluid supplied to the hydraulic cylinder means H for moving the pipes together to pull the joint, while a pressure gauge corresponding to gauge 114 of FIG. 12 may be used to indicate the discharge from valve 66' to ex tend the clamping means C and C in tensioning the belt, webbing or the like around the pipe.

Although this invention has been described as useful for a pipe having a spigot end and a bell end, it will be understood that these terms encompass pipes having interfitting ends similar to a groove or dovetail joint, to pipes whose ends fit with a sleeve or separate joint for both pipes, as well as other variations of pipe joints.

Although different embodiments of this invention have been illustrated and described, it will be understood that other embodiments may exist and that various changes may be made therein, all without departing from the spirit and scope of this invention.

What is claimed is:

1. A device for forming a pipe joint in a trench by moving a spigot end of one pipe section into the bell end of an adjacent, second pipe section, said pipe sections being in alignment, comprising:

a first base for engaging said one pipe section adjacent the spigot end thereof but spaced sufficiently from said end to permit movement of said end into said bell end of said second pipe;

a second base for engaging said second pipe section adjacent said bell end thereof;

a first clamping device mounted on said first base for attaching said first base to said first pipe section;

a second clamping device mounted on said second base for attaching said second base to said second pipe section;

telescoping, rigidifying means connecting said bases for relative longitudinal movement thereof;

means for moving said connecting means, to move said bases toward each other for moving said first pipe section spigot end into said bell end of said second pipe section and to move said bases away from each other to position said bases for clamping the pipe sections at the next joint; and

roller means for engaging said pipe and moving said device from a completed joint to the next joint, including rollers resiliently mounted adjacent opposite ends of said respective bases to elevate said bases above a pipe section when said clamping devices are released, and to permit said bases to move into engagement with the respective pipe sections when said clamping device are tensioned.

2. A device as defined in claim 1, including:

auxiliary rollers spaced relatively closely together at the front end of said first base for lifting said base over the bell end of a pipe section.

3. In a device as defined in claim 1, wherein:

each said base is concave on the underside.

4. In a device as defined in claim 1, wherein:

said rigidifying means connecting said bases includes an elongated guide member mounted on one of said bases and an elongated member slidable in said guide member and connected to the opposite base.

5. In a device as defined in claim 4, wherein:

said means for moving said connecting means includes hydraulically operated means connected to said slidable member and mounted on the same base as said guide member.

6. In a device as defined in claim 5, wherein:

said hydraulic means is mounted within said slidable member but connected to said slidable member and to said guide member.

7. In a device as defined in claim 5, wherein:

said hydraulic means is disposed below said guide member and is connected to a depending, transverse part affixed to said slidable member.

8. In a device as defined in claim 4, wherein:

one of said clamping devices is mounted on said elongated guide member.

9. In a device as defined in claim 4, wherein:

both said guide member and said slidable member are hollow and cylindrical;

an upstanding post is mounted on the opposite base;

a longitudinal tube is mounted on top of said post;

and

a shaft is affixed to an end of said slidable member and removably connected to said longitudinal tube.

10. In a device as defined in claim 4, wherein:

both said guide member and said slidable member are hollow and generally rectangular in crosssection but having rounded corners.

11. In a device as defined in claim 10, wherein:

said means for moving said connecting means includes a hydraulic cylinder within said slidable member and pivotally connected at one end to opposite sides of said guide member, said slidable member having notches to accommodate said pivot connection; and

a piston rod extends from the opposite end of said cylinder and is pivotally connected to the sides of the opposite end of said guide member.

12. In a device as defined in claim 4, including:

a flexible cover for the area of said slidable member exposed beyond one end of said guide member; and

a flexible cover for the area of said slidable member exposed beyond the opposite end of said guide member;

each said flexible cover being attached to said guide member and said slidable member and adapted to protect a lubricant applied to said slidable member from dirt, debris and the like.

13. A device as defined in claim 1, said roller means including:

a pair of rollers at the ends of the respective bases for engaging said pipe and moving said device from a completed joint to the next joint;

shaft means extending transversely of the respective base and mounting said rollers for rotation;

a series of springs associated with each said shaft means for elevating said bases above a pipe section, when said clamping devices are released, and permitting the bases to move into engagement with said pipe sections, when said clamping devices are tensioned;

means for guiding said shaft means for up and down movement; and

means for limting downward movement of said shaft means when said device is removed from a pipe, with said clamping devices released.

14. In a device as defined in claim 13, wherein:

said shaft means is constructed and arranged so that the position of said rollers is adjustable laterally, whereby said rollers of each set may be spaced closer together for pipe of a lesser diameter and spaced further apart for pipe of a greater diameter.

15. A device as defined in claim 1, wherein: each said clamping device is operable hydraulically;

said means for moving said connecting means is operated hydraulically;

an electrical motor and hydraulic pump are mounted on said first base above said telescoping, rigidifying means;

a storage battery for supplying current to said electrical motor is mounted alongside said motor and hydraulic pump; and

control valves for controlling the flow of hydrauic fluid to and from each of said hydraulic means are mounted adjacent said motor and hydraulic pump.

16. In a device as defined in claim 15, wherein:

each said base includes a plate having depending side flanges whose lower edges engage a pipe, and depending end flanges having a concave, arcuate lower edge;

said telescoping, rigidifying means includes an outer cylindrical guide tube mounted on said first base in a position spaced above said plate, and an inner tube slidable within said outer tube, said guide tube extending to the inner end of said first base and said slidable tube extending from both ends of said guide tube;

said slidable tube is provided with a depending member at the end which extends over said first base and is connected, at the opposite end, to said second base;

said connection between said slidable tube and said second base includes an upstanding post mounted on said plate of said second base, a longitudinally extending tube mounted on top of said post, a shaft attached to the corresponding end of said slidable tube and extending within said longitudinal tube, and removable means connecting said shaft to said longitudinal tube;

said means for moving said connecting means includes a hydraulic cylinder mounted on said first base below said guide tube and having a piston rod extending therefrom toward and connected to said depending member of said slide tube;

a flexible cover, at each end of said guide tube, disposed around the area of said slidable tube exposed on movement in either direction;

one said clamping device is mounted on the plate of said second base and the other said clamping device is mounted on a bracket attached to the top of said guide tube;

each said clamping device includes a centrally disposed, upright hydraulic cylinder having a piston rod extending upwardly therefrom, an upright, fixed guide rod, at each side of said hydraulic cylinder, a tubular slide engaging each guide rod for movement upwardly and downwardly thereon, and a cross bar connecting the upper ends of said slides and attached centrally on the underside to said piston rod;

a hook for a chain or the like is mounted on the lateral side of each said slide;

a pair of laterally spaced rollers are disposed at the end of each said base and are mounted for rotation on stub shafts carried by an axle;

a pair of spaced, upright boxes, open at the lower ends, are attached to the end of said plate of said first base, and an upright slot in each side of each box guides said axle upwardly and downwardly;

said upstanding pin is mounted on said axle, at the center of each said box, and extends upwardly through the top of said box, with a stop device at the upper end of each pin above said box;

a compression spring surrounds each said pin and acts between said axle and the underside of the top of said box;

a pair of casters are inclined toward each other at the end of said first base, with a compression spring surrounding a post of each caster;

a bracket is attached to the end of each said box and has means for receiving said spring and post;

an elongated box is attached to the end of said plate of said second base and has end slots for guiding said axle for up and down movement;

a series of pins is mounted on and upstands from said axle to extend upwardly through said box, while a spring surrounds each pin;

retaining means at the top of each said pin, above said box, limits downward movement of said axle and attaches said pins to a laterally extending bar; and

said stub shafts for said rollers of said second base extend laterally beyond said rollers, with means connecting said stub shafts with the extended ends of said transverse bar.-

17. In a device as defined in claim 15, wherein:

each said base includes a plate having depending side flanges, the lower edges of which are engageable with a pipe section, and depending end flanges having a concave, arcuate lower edge;

I said telescoping, rigidifying means includes an outer tube having a rectangular cross section, but with rounded corners, mounted above said plate of said first base, and an inner tube slidable within said outer tube and having a corresponding rectangular cross section, but with rounded corners;

said second base is provided with a bracket upstanding from the inner end of said plate, the end of said inner tube being attached thereto;

said means for moving said connecting means includes a hydraulic cylinder disposed within said inner tube but pivotally connected at the open end to the side walls of said outer tube, said inner tube having a notch at each side to clear said cylinder connection to said outer tube;

a piston rod extends from the opposite end of said hydraulic cylinder and is pivotally connected to the inside of the side walls of said inner tube adjacent said bracket of said second base;

hoses extend from said control valve means to said hydraulic cylinder, into the open end of said inner tube;

one hydraulic clamping device is mounted atop said outer tube adjacent the open end thereof and the other on said plate of said second base;

each said clamping device includes an upright hydraulic cylinder having a piston rod extending upwardly therefrom, a fixed guide tube surrounding said cylinder and having a rectangular cross section, but with rounded corners, a slide tube having a corresponding cross section and engaging the outside of said guide tube, a plate closing the top of said sliding tube and connected to the end of said piston rod, and a pair of hooks mounted on the sides of said slide tube for engagement with a chain or the like;

a pair of laterally spaced rollers are each mounted on a stub shaft at the respective front and rear ends of said bases, said stub shafts being adjustable within a transverse axle housing, whereby said rollers may be adjusted laterally toward and away from each other;

a bracket upstands from the end of each base plate;

a series of tubes is mounted on each said bracket,

above said axle housing;

a series of pins upstands from said axle and extends upwardly into the respective tubes;

a compression spring surrounds each pin within said tube;

a disc is fixed transversely within each tube and is abutted by the top of the corresponding spring, said pin extending through each fixed disc;

a disc within each tube is fixed to each pin for abutment by the lower end of the corresponding spring; and

stop means at the lower end of each tube restrains movement of said pin disc downwardly out of said tube.

18. A device for moving a spigot end of one pipe section into the bell end of an adjacent, second pipe section, said pipe sections being in alignment, including:

a first base for engaging said one pipe section adjacent the spigot end thereof but spaced sufficiently from said end to permit movement of said end into said bell end of said second pipe;

a second base for engaging said second pipe section adjacent said bell end thereof;

a first clamping device mounted on said first base for attaching said first base to said first pipe section;

a second clamping device mounted on said second base for attaching said second base to said second pipe section;

telescoping, rigidifying means connecting said bases for relative longitudinal movement thereof;

means for moving said connecting means, to move said bases toward each other for moving said first pipe section spigot end into said bell end of said second pipe section and to move said bases away from each other to position said bases for clamping the pipe sections at the next joint; and

each said clamping device includes:

an upright hydraulic cylinder and a piston rod extending upwardly therefrom;

an upstanding guide means disposed on at least opposite sides of the said cylinder;

means slidable upwardly and downwardly along said guide means and extending across the area above said cylinder for connection of the underside thereof to said piston rod; and

a hook device attached to the outside of said slidable means on each side thereof, and adapted to engage a selected link of a chain or the like, whereby a band extending between said chain links around a pipe will be clamped against said pipe upon upward extension of said piston rod and said base on which said clamping device is mounted also will be clamped against said pipe. 

1. A device for forming a pipe joint in a trench by moving a spigot end of one pipe section into the bell end of an adjacent, second pipe section, said pipe sections being in alignment, comprising: a first base for engaging said one pipe section adjacent the spigot end thereof but spaced sufficiently from said end to permit movement of said end into said bell end of said second pipe; a second base for engaging said second pipe section adjacent said bell end thereof; a first clamping device mounted on said first base for attaching said first base to said first pipe section; a second clamping device mounted on said second base for attaching said second base to said second pipe section; telescoping, rigidifying means connecting said bases for relative longitudinal movement thereof; means for moving said connecting means, to move said bases toward each other for moving said first pipe section spigot end into said bell end of said second pipe section and to move said bases away from each other to position said bases for clamping the pipe sections at the next joint; and roller means for engaging said pipe and moving said device from a completed joint to the next joint, including rollers resiliently mounted adjacent opposite ends of said respective bases to elevate said bases above a pipe section when said clamping devices are released, and to permit said bases to move into engagement with the respective pipe sections when said clamping device are tensioned.
 2. A device as defined in claim 1, including: auxiliary rollers spaced relatively closely together at the front end of said first base for lifting said base over the bell end of a pipe section.
 3. In a device as defined in claim 1, wherein: each said base is concave on the underside.
 4. In a device as defined in claim 1, wherein: said rigidifying means connecting said bases includes an elongated guide member mounted on one of said bases and an elongated member slidable in said guide member and connected to the opposite base.
 5. In a device as defined in claim 4, wherein: said means for moving said connecting means includes hydraulically operated means connected to said slidable member and mounted on the same base as said guide member.
 6. In a device as defined in claim 5, wherein: said hydraulic means is mounted within said slidable member but connected to said slidable member and to said guide member.
 7. In a device as defined in claim 5, wherein: said hydraulic means is disposed below said guide member and is connected to a depending, transverse part affixed to said slidable member.
 8. In a device as defined in claim 4, wherein: one of said clamping devices is mounted on said elongated guide member.
 9. In a device as defined in claim 4, wherein: both said guide member and said slidable member are hollow and cylindrical; an upstanding post is mounted on the opposite base; a longitudinal tube is mounted on top of said post; and a shaft is affixed to an end of said slidable member and removably connected to said longitudinal tube.
 10. In a device as defined in claim 4, wherein: both said guide member and said slidable member are hollow and generally rectangular in cross-section but having rounded corners.
 11. In a device as defined in claim 10, wherein: said means for moving said connecting means includes a hydraulic cylinder within said slidable member and pivotally connected at one end to opposite sides of said guide member, said slidable member having notches to accommodate said pivot connection; and a piston rod extends from the opposite end of said cylinder and is pivotally connected to the sides of the opposite end of said guide member.
 12. In a device as defined in claim 4, including: a flexible cover for the area of said slidable member exposed beyond one end of said guide member; and a flexible cover for the area of said slidable member exposed beyond the opposite end of said guide member; each said flexible cover being attached to said guide member and said slidable member and adapted to protect a lubricant applied to said slidable member from dirt, debris and the like.
 13. A device as defined in claim 1, said roller means including: a pair of rollers at the ends of the respective bases for engaging said pipe and moving said device from a completed joint to the next joint; shaft means extending transversely of the respective base and mounting said rollers for rotation; a series of springs associated with each said shaft means for elevating said bases above a pipe section, when said clamping devices are released, and permitting the bases to move into engagement with said pipe sections, when said clamping devices are tensioned; means for guiding said shaft means for up and down movement; and means for limting downward movement of said shaft means when said device is removed from a pipe, with said clamping devices released.
 14. In a device as defined in claim 13, wherein: said shaft means is constructed and arranged so that the position of said rollers is adjustable laterally, whereby said rollers of each set may be spaced closer together for pipe of a lesser diameter and spaced further apart for pipe of a greater diameter.
 15. A device as defined in claim 1, wherein: each said clamping device is operable hydraulically; said means for moving said connecting means is operated hydraulically; an electrical motor and hydraulic pump are mounted on said first base above said telescoping, rigidifying means; a storage battery for supplying current to said electrical motor is mounted alongside said motor and hydraulic pump; and control valves for controlling the flow of hydrauic fluid to and from each of said hydraulic means are mounted adjacent said motor and hydraulic pump.
 16. In a device as defined in claim 15, wherein: each said base includes a plate having depending side flanges whose lower edges engage a pipe, and depending end flanges having a concave, arcuate lower edge; said telescoping, rigidifying means includes an outer cylindrical guide tube mounted on said first base in a position spaced above said plate, and an inner tube slidable within said outer tube, said guide tube extending to the inner end of said first base and said slidable tube extending from both ends of said guide tube; said slidable tube is provided with a depending member at the end which extends over said first base and is connected, at the opposite end, to said second base; said connection between said slidable tube and said second base includes an upstanding post mounted on said plate of said second base, a longitudinally extending tube mounted on top of said post, a shaft attached to the corresponding end of said slidable tube and extending within sAid longitudinal tube, and removable means connecting said shaft to said longitudinal tube; said means for moving said connecting means includes a hydraulic cylinder mounted on said first base below said guide tube and having a piston rod extending therefrom toward and connected to said depending member of said slide tube; a flexible cover, at each end of said guide tube, disposed around the area of said slidable tube exposed on movement in either direction; one said clamping device is mounted on the plate of said second base and the other said clamping device is mounted on a bracket attached to the top of said guide tube; each said clamping device includes a centrally disposed, upright hydraulic cylinder having a piston rod extending upwardly therefrom, an upright, fixed guide rod, at each side of said hydraulic cylinder, a tubular slide engaging each guide rod for movement upwardly and downwardly thereon, and a cross bar connecting the upper ends of said slides and attached centrally on the underside to said piston rod; a hook for a chain or the like is mounted on the lateral side of each said slide; a pair of laterally spaced rollers are disposed at the end of each said base and are mounted for rotation on stub shafts carried by an axle; a pair of spaced, upright boxes, open at the lower ends, are attached to the end of said plate of said first base, and an upright slot in each side of each box guides said axle upwardly and downwardly; said upstanding pin is mounted on said axle, at the center of each said box, and extends upwardly through the top of said box, with a stop device at the upper end of each pin above said box; a compression spring surrounds each said pin and acts between said axle and the underside of the top of said box; a pair of casters are inclined toward each other at the end of said first base, with a compression spring surrounding a post of each caster; a bracket is attached to the end of each said box and has means for receiving said spring and post; an elongated box is attached to the end of said plate of said second base and has end slots for guiding said axle for up and down movement; a series of pins is mounted on and upstands from said axle to extend upwardly through said box, while a spring surrounds each pin; retaining means at the top of each said pin, above said box, limits downward movement of said axle and attaches said pins to a laterally extending bar; and said stub shafts for said rollers of said second base extend laterally beyond said rollers, with means connecting said stub shafts with the extended ends of said transverse bar.
 17. In a device as defined in claim 15, wherein: each said base includes a plate having depending side flanges, the lower edges of which are engageable with a pipe section, and depending end flanges having a concave, arcuate lower edge; said telescoping, rigidifying means includes an outer tube having a rectangular cross section, but with rounded corners, mounted above said plate of said first base, and an inner tube slidable within said outer tube and having a corresponding rectangular cross section, but with rounded corners; said second base is provided with a bracket upstanding from the inner end of said plate, the end of said inner tube being attached thereto; said means for moving said connecting means includes a hydraulic cylinder disposed within said inner tube but pivotally connected at the open end to the side walls of said outer tube, said inner tube having a notch at each side to clear said cylinder connection to said outer tube; a piston rod extends from the opposite end of said hydraulic cylinder and is pivotally connected to the inside of the side walls of said inner tube adjacent said bracket of said second base; hoses extend from said control valve means to said hydraulic cylinder, into the open end of said inner tube; one hydraulic clamping device is mounted atop said outer tube adjacent the open end thereof and the other on said plate of said second base; each said clamping device includes an upright hydraulic cylinder having a piston rod extending upwardly therefrom, a fixed guide tube surrounding said cylinder and having a rectangular cross section, but with rounded corners, a slide tube having a corresponding cross section and engaging the outside of said guide tube, a plate closing the top of said sliding tube and connected to the end of said piston rod, and a pair of hooks mounted on the sides of said slide tube for engagement with a chain or the like; a pair of laterally spaced rollers are each mounted on a stub shaft at the respective front and rear ends of said bases, said stub shafts being adjustable within a transverse axle housing, whereby said rollers may be adjusted laterally toward and away from each other; a bracket upstands from the end of each base plate; a series of tubes is mounted on each said bracket, above said axle housing; a series of pins upstands from said axle and extends upwardly into the respective tubes; a compression spring surrounds each pin within said tube; a disc is fixed transversely within each tube and is abutted by the top of the corresponding spring, said pin extending through each fixed disc; a disc within each tube is fixed to each pin for abutment by the lower end of the corresponding spring; and stop means at the lower end of each tube restrains movement of said pin disc downwardly out of said tube.
 18. A device for moving a spigot end of one pipe section into the bell end of an adjacent, second pipe section, said pipe sections being in alignment, including: a first base for engaging said one pipe section adjacent the spigot end thereof but spaced sufficiently from said end to permit movement of said end into said bell end of said second pipe; a second base for engaging said second pipe section adjacent said bell end thereof; a first clamping device mounted on said first base for attaching said first base to said first pipe section; a second clamping device mounted on said second base for attaching said second base to said second pipe section; telescoping, rigidifying means connecting said bases for relative longitudinal movement thereof; means for moving said connecting means, to move said bases toward each other for moving said first pipe section spigot end into said bell end of said second pipe section and to move said bases away from each other to position said bases for clamping the pipe sections at the next joint; and each said clamping device includes: an upright hydraulic cylinder and a piston rod extending upwardly therefrom; an upstanding guide means disposed on at least opposite sides of the said cylinder; means slidable upwardly and downwardly along said guide means and extending across the area above said cylinder for connection of the underside thereof to said piston rod; and a hook device attached to the outside of said slidable means on each side thereof, and adapted to engage a selected link of a chain or the like, whereby a band extending between said chain links around a pipe will be clamped against said pipe upon upward extension of said piston rod and said base on which said clamping device is mounted also will be clamped against said pipe. 